How to randomise colors (just 6 colours) - Processing Forum

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archstud

How to randomise colors (just 6 colours)

in Programming Questions • 3 years ago

Hi all,

I'm new to processing so I hope you can help!

So heres my code:

void setup(){
size(700, 700);
smooth();
background(0);
}

void draw(){

stroke(255,8,8);
noFill();
strokeWeight(50);
arc(700, 700, 1300, 1300, PI, TWO_PI-PI/2);

stroke(255,153,0);
noFill();
strokeWeight(50);
arc(700, 700, 1200,1200, PI, TWO_PI-PI/2);

stroke(255,234,0);
noFill();
strokeWeight(50);
arc(700, 700, 1100, 1100, PI, TWO_PI-PI/2);

stroke(0,255,1);
noFill();
strokeWeight(50);
arc(700, 700, 1000, 1000, PI, TWO_PI-PI/2);

stroke(26,230,255);
noFill();
strokeWeight(50);
arc(700, 700, 900, 900, PI, TWO_PI-PI/2);

stroke(186,3,255);
noFill();
strokeWeight(50);
arc(700, 700, 800, 800, PI, TWO_PI-PI/2);
}

What I'm having trouble with is trying to get each rainbow arc to randomly change to any one of the six colors.

Thanks in advance for any replies!

1

Replies(4)

amnon.owed

amnon.owed

Re: How to randomise colors (just 6 colours)

3 years ago

Some suggestions.

Commands like noFill and strokeWeight hold for everything that comes after it; until set otherwise. In other words, in this case you can just set it up once, for example in setup.
For repetitive stuff, you can use a FOR loop.
For random behavior you can use the random function.

Here is a basic code example showing those things. I've slowed down the frameRate a little in this case.

color c0 = color(255,8,8);
color c1 = color(255,153,0);
color c2 = color(255,234,0);
color c3 = color(0,255,1);
color c4 = color(26,230,255);
color c5 = color(186,3,255);
void setup() {
size(700,700);
frameRate(6);
smooth();
noFill();
strokeWeight(50);
}
void draw() {
background(0);
for (int i=0; i<6; i++) {
int randomColor = int(random(6));
if (randomColor == 0) { stroke(c0); }
if (randomColor == 1) { stroke(c1); }
if (randomColor == 2) { stroke(c2); }
if (randomColor == 3) { stroke(c3); }
if (randomColor == 4) { stroke(c4); }
if (randomColor == 5) { stroke(c5); }
arc(700, 700, 800 + i*100, 800 + i*100, PI, TWO_PI-PI/2);
}
}

archstud

Re: Re: How to randomise colors (just 6 colours)

3 years ago

Wow thank you so much! I really appreciate you taking the time to also explain the coding and for the suggestions and links! It has been very useful!

kooogy

Re: Re: How to randomise colors (just 6 colours)

3 years ago

this:

color c0 = color(255,8,8);
color c1 = color(255,153,0);
color c2 = color(255,234,0);
color c3 = color(0,255,1);
color c4 = color(26,230,255);
color c5 = color(186,3,255);

is crying out for an array. which would also reduce those 6 if statements in the draw() to a single line.

amnon.owed

amnon.owed

Re: How to randomise colors (just 6 colours)

3 years ago

Oh, you're right. Hadn't even thought about it.

Updated version, which also includes a few alternative methods ( noise, sin, modulo) to go through the color array.

color[] colors = new color[6];
void setup() {
size(700,700);
frameRate(6);
smooth();
noFill();
strokeWeight(50);
colors[0] = color(255,8,8);
colors[1] = color(255,153,0);
colors[2] = color(255,234,0);
colors[3] = color(0,255,1);
colors[4] = color(26,230,255);
colors[5] = color(186,3,255);
}
void draw() {
background(0);
for (int i=0; i<6; i++) {
stroke(colors[int(random(6))]);
// stroke(colors[int(noise(frameCount+i)*5)]);
// stroke(colors[int(abs(sin(frameCount+i))*5)]);
// stroke(colors[(frameCount+i)%5]);
arc(700, 700, 800 + i*100, 800 + i*100, PI, TWO_PI-PI/2);
}
}

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